• Authors:
    • Afiuni, D.
    • Bagheri, M.
  • Source: Seed and Plant Improvement Journal
  • Volume: 26-1
  • Issue: 2
  • Year: 2010
  • Summary: Wheat thrips, Haplothrips tritici K. (Thy.: Thripidae) is an important pest of cereals. Host plant resistance is a useful method recommended for controlling the pest. An experiment was conducted in a randomized complete block design with fifteen wheat cultivars and advanced line and four replications in two separate parts in Golpaygan area, Isfahan province during 2000-2002. One part of the experiment was sprayed four times with Fenitrothion (mlha -1) and the other part with water simultaneously. Sampling of the pest population in each plot was done through counting the number of adult thripses collected in ten sweep nets at flowering stage, and nymphs on ten ears at milky and ripening stages. At harvesting time, grain yield and TKW were also assessed. Combined analysis show no significant differences among cultivars for adult population and significant differences (p≤0.01) for nymph population. Shotor dandan and Roshan cultivars had the lowest and M-78-20 and Barekat had the highest density of nymphs (8.69, 8.73, 20.9 and 19.71 nymph/spike, respectively) and showed significant differences with other cultivars. Barekat cultivar, in spite of its high density of nymph/spike, had the lowest SSI for TKW, percentage of TKW loss and grain yield loss. Pishtaz cultivar having the highest quantity of mentioned factors was the most susceptible cultivar. Differences between sprayed and non-sprayed parts for yield were not significant but for TKW was significant (p≤0.01).
  • Authors:
    • Riffkin, P.
    • MacEwan, R.
    • Clough, A.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Symposium 4.2.1 Soil, energy and food security
  • Year: 2010
  • Summary: Dryland cropping in the high rainfall zone (HRZ) of southern Australia has the potential to produce high yields of cereals, canola and pulses. However, actual yields often fall well short of the estimated potential. A survey of grain growers in the HRZ was conducted to gain a greater understanding of the factors which may prevent growers from achieving potential yields. The survey was developed in consultation with growers, soil scientists and agronomists and distributed nationally through an industry magazine. The survey captured grower perceptions of soil and crop management using multiple choice questions and free comment sections. This paper documents the section of the survey pertaining to soils. In this survey, growers throughout the HRZ provided common responses regarding their use of some forms of tillage, trafficking, chemical soil amelioration techniques and physical soil engineering techniques. Different responses were evident depending upon region and farm size for issues such as the use of conventional tillage, raised beds and lime. The perceived success of various types of soil management options is also discussed. This information is valuable for those who wish to identify which regions or grower audiences should be targeted for research and extension in soil management.
  • Authors:
    • Gregorio, P.
    • Lupi, S.
    • Cucchi, A.
  • Source: Tecnica Molitoria
  • Volume: 61
  • Issue: 1
  • Year: 2010
  • Summary: Feeding is the main route for trace elements intake. The amount of trace elements in the food ingested may result in a loss or accumulation of trace elements in different body tissues. The possible distribution of essential (chromium, manganese, copper, selenium and zinc) and toxic (cadmium) elements from the environment to the maize plant was evaluated in this study. Furthermore, their transfer from irrigation water, soil water, soil, corn plant, corn grain, and especially to corn flour was estimated. Sampling was conducted during the cropping season in two areas in Italy and the concentrations in different matrices have been compared to exclude differences related to irrigation and to assess element accumulation. The concentration of metals was lower in flour than in the grain; the processes of grinding led to an almost total loss of copper, cadmium, chromium and selenium, to a loss of more than 50% of zinc and of most of the manganese content.
  • Authors:
    • Pintar, M.
    • Tratnik, M.
    • Zupanc, V.
    • Cvejic, R.
  • Source: Novi izzivi v poljedelstvu 2010. Zbornik simpozija
  • Year: 2010
  • Summary: Optimal use of existing irrigation systems (IS) is as important as investments in new IS. Officially there are 52 IS in Slovenia, that are actively used, however less is known about how well they are being used. The paper overviews the cultures being represented on examined IS. The research, carried out for the period 2006-2009 indicates, that the examined IS are being used below its expected potentials. On average, the groups of cultures that are normally irrigated in Slovenia (orchards, ornamental plants, vegetables) cover 27% of the surface of IS, while the cultures that are normally not irrigated (forage crops, cereals, vineyards) cover 73%. The paper identifies the possible reasons for this situation, however further field research needs to be undertaken in the future to identify the influencing factors unambiguously and find possible solutions that would result in IS being used efficiently.
  • Authors:
    • Czekaa,J.
  • Source: Journal of Research and Applications in Agricultural Engineering
  • Volume: 55
  • Issue: 3
  • Year: 2010
  • Summary: The distribution of nitrogen in the soil in different chemical associations is a resultant of action of many factors of which three deserve mention: plants, nitrogen fertilization and sprinkling. The main objective of this research project was to analyze the impact of these factors, acting separately as well as jointly, in conditions of long-term plant cultivation without cereals, on the content of individual soil nitrogen forms. Sequential nitrogen determination of soil nitrogen forms was applied in the experiments which allowed identification of mineral nitrogen as well as its easily-, poorly-hydrolyzed and non hydrolysable forms It was found that sprinkling exerted the strongest, significant influence on the concentration of all examined nitrogen forms with the exception of the easily hydrolysable nitrogen fraction. This impact was also noticeable in the interaction with nitrogen doses, primarily in the content of mineral nitrogen forms and easily hydrolysable nitrogen. Irrespective of the experimental treatment, no significant effect of nitrogen applied in different doses on the examined forms of the component was recorded. On the other hand, the percentage proportion of nitrogen forms in total nitrogen depended significantly, primarily, on sprinkling irrigation and only in relation to mineral nitrogen forms.
  • Authors:
    • Talavari, F.
    • Asgharzadeh, A.
    • Dadnia, M.
  • Source: Research on Crops
  • Volume: 11
  • Issue: 3
  • Year: 2010
  • Summary: Increasing grain protein in new higher-yielding cereal grains has recently received added attention due to protein premiums paid to farmers. Winter wheat ( Triticum aestivum L.) studies were conducted during 2009 to evaluate the effects of late-season foliar N applications on grain yield. Foliar applications of N were made at spiking stage (Leaves foliar and N application with irrigation water), seed foliar and control treatments, using urea at rates of 90 and 120 kg N/ha. A significant difference in increase in grain yield was observed for leaves foliar applications in this study. In the present experiment, significant differences were observed for nitrogen levels. Consistent increases from foliar N applications were observed for grain yield. Leaves foliar applied (4 litre liquid N/ha) increased grain over that N applied with irrigation water (4 litre liquid N/ha) by 5.36 and 4.12 t/ha, respectively. Seed foliar applied (2 litre for 100 kg seed) increased grain yield than control treatments by 4.81 and 3.54 t/ha, respectively. Late-season foliar N applications before or immediately following flowering may significantly enhance grain yield content and, thus, per cent protein in winter wheat.
  • Authors:
    • Chen, D.
    • Dixit, P.
  • Source: Computers and Electronics in Agriculture
  • Volume: 74
  • Issue: 2
  • Year: 2010
  • Summary: High levels of subsoil salinity limit the growth and yield of dryland cereals in the Victorian southern Mallee, Australia. Currently available crop simulation models of wheat production perform poorly in this region, presumably due to their inability to account for subsoil limitations, mainly salinity. The objective of this work was to modify a spatially referenced Water and Nitrogen Management Model (WNMM) to account for the spatial pattern of subsoil salinity, by adjusting crop water uptake, in order to explain the spatial variation in wheat yield in this area. Measurements of above-ground biomass and yield of wheat, and the profile of soil salinity (0-80 cm) were made at 40 locations across an 88 ha paddock (35.78°S, 142.98°E) in the Victorian southern Mallee. The S-shaped water stress response function for crop water uptake proposed by van Genuchten (1987) was explored to modify the WNMM by adjusting the water uptake due to salinity, which significantly improved yield simulation over the original WNMM. The improvement in the model's ability to simulate wheat yield indicates that the subsoil salinity limits crop performance in the area. The incorporation of a salinity function in spatial crop models offers potential for simulating yield across a landscape and thus practicing precision agriculture provided salinity impact is considered dynamically.
  • Authors:
    • Zhang, J.
    • Zhang, X.
    • Sun, J.
    • Kang, S.
    • Du, T.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 1
  • Year: 2010
  • Summary: Water shortage is the major bottleneck that limits sustainable development of agriculture in north China. Crop physiological water-saving irrigation methods such as temporal (regulated deficit irrigation) and spatial (partial root zone irrigation) deficit irrigation have been tested with much improved crop water use efficiency (WUE) without significant yield reduction. Field experiments were conducted to investigate the effect of (1) spatial deficit irrigation on spring maize in arid Inland River Basin of northwest China during 1997-2000; (2) temporal deficit irrigation on winter wheat in semi-arid Haihe River Basin during 2003-2007 and (3) temporal deficit irrigation on winter wheat and summer maize in Yellow River Basin during 2006-2007. Results showed that alternate furrow irrigation (AFI) maintained similar photosynthetic rate ( Pn) but reduced transpiration rate ( Tr), and thus increased leaf WUE of maize. It also showed that the improved WUE might only be gained for AFI under less water amount per irrigation. The feasible irrigation cycle is 7d in the extremely arid condition in Inner River Basin of northwest China and less water amount with more irrigation frequency is better for both grain yield and WUE in semi-arid Haihe River Basin of north China. Field experiment in Yellow River Basin of north China also suggests that mild water deficit at early seedling stage is beneficial for grain yield and WUE of summer maize, and the deficit timing and severity should be modulated according to the drought tolerance of different crop varieties. The economical evapotranspiration for winter wheat in Haihe River Basin, summer maize in Yellow River Basin of north China and spring maize in Inland River Basin of northwest China are 420.0 mm, 432.5 mm and 450.0 mm respectively. Our study in the three regions in recent decade also showed that AFI should be a useful water-saving irrigation method for wide-spaced cereals in arid region, but mild water deficit in earlier stage might be a practical irrigation strategy for close-planting cereals. Application of such temporal and spatial deficit irrigation in field-grown crops has greater potential in saving water, maintaining economic yield and improving WUE.
  • Authors:
    • Abbaspour, K.
    • Schulin, R.
    • Yang, H.
    • Faramarzi, M.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 11
  • Year: 2010
  • Summary: In most parts of Iran, water scarcity has been intensifying and posing a threat to the sustainability of agricultural production. Wheat is the dominant crop and the largest irrigation water user in Iran; hence, understanding of the crop yield-water relations in wheat across the country is essential for a sustainable production. Based on a previously calibrated hydrologic model, we modeled irrigated and rainfed wheat yield ( Y) and consumptive water use ( ET) with uncertainty analysis at a subbasin level in Iran. Simulated Y and ET were used to calculate crop water productivity ( CWP). The model was then used to analyze the impact of several stated policies to improve the agricultural system in Iran. These included: increasing the quantity of cereal production through more efficient use of land and water resources, improving activities related to soil moisture conservation and retention, and optimizing fertilizer application. Our analysis of the ratio of water use to internal renewable water resources revealed that 23 out of 30 provinces were using more than 40% of their water resources for agriculture. Twelve provinces reached a ratio of 100% and even greater, indicating severe water scarcity and groundwater resource depletion. An analysis of Y-CWP relationship showed that one unit increase in rainfed wheat yield resulted in a lesser additional water requirement than irrigated wheat, leading to a larger improvement in CWP. The inference is that a better water management in rainfed wheat, where yield is currently small, will lead to a larger marginal return in the consumed water. An assessment of improvement in soil available water capacity ( AWC) showed that 18 out of 30 provinces are more certain to save water while increasing AWC through proper soil management practices. As wheat self-sufficiency is a desired national objective, we estimated the water requirement of the year 2020 (keeping all factors except population constant) to fulfill the wheat demand. The results showed that 88% of the additional wheat production would need to be produced in the water scarce provinces. Therefore, a strategic planning in the national agricultural production and food trade to ensure sustainable water use is needed. This study lays the basis for a systematic analysis of the potentials for improving regional and national water use efficiency. The methodology used in this research, could be applied to other water scarce countries for policy impact analysis and the adoption of a sustainable agricultural strategy.
  • Authors:
    • Xanthoulis, D.
    • Heens, B.
    • Fonder, N.
  • Source: Biotechnologie, Agronomie, Société et Environnement
  • Volume: 14
  • Issue: S1
  • Year: 2010
  • Summary: Experiments were performed over four years, testing five cultivations to optimise mineral nitrogen fertilisation when irrigation with wastewater occurs. The experimental site was located inside an irrigated perimeter around the agro-food industry Hesbaye Frost, producing frozen vegetables, in Belgium. Depending on the crop rotation adopted by the farmer, four vegetable cultivations (spinach, bean, carrot and broad bean) and one cereal (winter wheat) were tested. Because of the time required for implementation of the experiment and meteorological conditions, the irrigation factor was not tested for spinach (1999) and wheat (2000) cultivations. The two experimental factors were three fertilisation levels, with comparison to a reference without any mineral nitrogen supply, and irrigation with or without wastewater. These factors were assessed for their impacts on crop yields and mineral nitrogen residues in the soil after harvest. The three vegetable cultivations of bean, carrot and broad bean were irrigated and systematically presented statistically higher yields with wastewater irrigation supply than without. The fertilisation factor also significantly improved all the yields, or protein rate for cereal cultivation, except for carrot and broad bean where differences were not significant, even for the zero fertilisation rate. The nitrogen residues in the soil after harvest were acceptable and regular as long as the fertilisation advice was not exceeded; the maximum fertilisation level tested, 50% higher than the recommendation, systematically left unacceptable nitrogen residues in the soil, harmful for the environment. Mainly located on the top surface horizon layers, the nitrogen residues could be held back by a catch crop classified as a nitrogen trap, with the condition to be set on late summer, with fall being considered as too late to have any influence to avoid nitrogen leaching. For all fertilisation levels, nitrogen residues were too high for the broad beans cultivation because of the phenomenon of surface mineral nitrogen release, due to meteorological conditions and the wastewater high nitrogen load brought by irrigation. The nitrogen residues under conditions of no irrigation were higher than under irrigation. Irrigation allowed better nitrogen solubility, easier for uptake by the plants and thus left fewer residues in the soil.